Heavy snow, upwards of 2-3′, is possible over portions of Pennsylvania, New Jersey, New York, Vermont, New Hampshire, and Massachusetts.

A powerful blizzard continues to blast the northeast with heavy snow, damaging winds, and rising coastal tides leading to flooding at the shore.

The storm has moved further west than originally expected, pushing the snow/sleet/rain line further inland as a result. The storm continues to evolve and wobble; areas that saw snow change to sleet this morning will see a change-over back to snow. Areas that saw plain rain and freezing rain in portions of central and western New Jersey will change back to sleet and perhaps snow. Rain falling over far southern New Jersey, central and southern Delaware, and eastern Maryland will remain as rain with little to no accumulation expected.

While the snow/sleet/rain line moved inland, it also brought more moisture in for this storm to play with. As a result, even more snow is expected than before over northeastern Pennsylvania, northwestern New Jersey, parts of eastern upstate New York, and some higher mountain areas of Massachusetts, Vermont, and New Hampshire.

Beyond the heavy snow, strong, potentially damaging winds are increasing in intensity and coverage. These winds will be especially problematic over New Jersey, Long Island, Connecticut, Massachussets, Rhode Island, and Maine. Power outages continue to grow and many may be without power over a prolonged period of time. Strong winds combined with heavy precipitation could topple trees, wires, or both, leading to numerous long-lasting problems in the region.

Flood threats continue at the shore: with the high tide cycle here, there is considerable storm surge flooding underway at the Jersey Shore and more of the same can be expected at the next high tide cycle for New England. Remember, never drive through flood waters: turn around, don’t drown.

A crippling blizzard with epic snow amounts is about to strike the northeastern US and everyone there should brace for its impacts.

The National Weather Service has raised Blizzard Warnings for a large area now with blizzard conditions now expected to be sustained over several hours.

While most people associate a large snow storm with the word “blizzard”, that is meteorologically incorrect. Blizzards are defined by their winds and visibility; it is even possible to have a blizzard without any fresh snow falling. To meet blizzard criteria, bad weather conditions need to persist for more than 3 hours: namely, winds need to be at 35mph or more and visibility due to either fresh falling snow or blowing fallen snow needs to be reduced down to a quarter mile or less.

You don’t need to have blizzard conditions to have dangerous snow storm conditions. Blowing snow is wind-driven snow that reduces visibility. Blowing snow may be falling snow or it could be snow on the ground that is picked up by the wind. Snow flurries are typically defined as light snow falling for short duration with little to no accumulation while snow showers are known for snowfall at varying intensity for brief periods of time with light accumulations. Snow squalls, however, are severe, brief, intense snow showers accompanied by strong, gusty winds, and while short-lived, snow squalls can produce quick and significant accumulations. In and after snow storms, snow squalls can threaten a region with additional hazards.

Most of the rest of the northeast is under a Winter Storm Warning for heavy snow. While a Blizzard Warning is not yet up beyond the above counties, blizzard conditions are likely at times for places like Philadelphia and Boston as strong winds and heavy snow drop visibility from time to time …and just not at the 3-hour required period that must be sustained to reach full blizzard criteria.

Beyond heavy snow will be powerful, destructive winds. These winds will be especially severe at the immediate coast where some damage to homes and business will be possible. Strong sustained winds and damaging wind gusts will extend far inland, setting the stage for widespread power failures. Due to the depth of the snow and severity of the storm, some power outages may last for many days.

The coast will also be battered by violent surf; major coastal flooding and beach erosion are also possible, especially for the Jersey Shore and southeastern New England coast where conditions are expected to be their worst. Flood guidance for places like Atlantic City, NJ is calling for major flood problems during the Tuesday morning high tide cycle. Blow-out tides are also possible, especially for Jersey back bays, as the storm pulls away.

Widespread 1-2′ snows will impact the northeast late tonight into tomorrow and Wednesday morning. Some isolated 2-3′ amounts are possible too.

Snow will be extremely heavy, with widespread 1-2 feet amounts expected. Strong winds will help blow and drift snow around, even though most snow will be of the heavy, wet variety. Drifts may exceed 4′ in places. There’s also the chance of very isolated 2-3′ amounts, especially over the higher terrain from northeastern Pennsylvania north and east into central New England.

Snow will fall at exceptionally heavy rates in excess of 2″/hr; some snowfall rates may even reach a nearly unfathomable 5″/hr. This heavy snow will make it difficult to travel, let alone walk, with blinding visibility made worse by blowing snow in damaging wind gusts. Do NOT plan to venture out during the storm, especially in the Winter Storm Warning and Blizzard areas.

When thunder roars, head indoors; lightning can kill in any season. While thunderstorms are typically associated with warmer weather, thunderstorms do pop up in intense winter storms. Lightning in a snow thunderstorm is just as dangerous as lightning in its warmer-weather sibling. The acoustics of fresh snow cover and a landscape typically free of leaves can also help make thunder sound more dramatic than it does at other times of the year. While some may be mesmerized by the sounds and scenes of thunderstorms inside snowstorms, people must remember that a thunderstorm at any time of year in any kind of weather is dangerous. Numerous thunder snowstorms are likely with this storm.

This will be a crippling snowstorm that will take an extended amount of time to recover from. All modes of transportation will be impacted and it may take more than 36 hours to restore access and service to some.

According to Flightaware, there are already 1,160 flight cancellations today, 952 for Tuesday, and already 32 cancellations for Wednesday. We expect these numbers to dramatically increase as the storm intensifies and nears the northeast.

A potent storm system will bring blizzard conditions to a large part of the northeast; heavy snow will also fall over a large area from late Monday through early Wednesday.

A crippling blizzard will impact the northeast later Monday into Tuesday before wrapping up early Wednesday morning. While heavy snow will fall out of the sky onto many, coastal areas will be impacted by damaging winds, significant high wave action, coastal flooding, and major beach erosion.

High pressure will continue to build into the northeast today, allowing clear skies for much of the region tonight. Some mid-level clouds will begin to move into the northeast late tonight, spilling over from an approaching flat upper ridge. With recent snow covering the terrain over central and northern Pennsylvania and New Jersey, New York, and southeastern New England, along with diminishing winds, temperatures will drop significantly tonight. Expect partly to mostly cloudy skies from New York City and points north and west by tomorrow morning as the flow across the eastern two thirds of the continental US begins to amplify.

Powerful wind gusts will create their own set of problems in the northeast as the storm pushes up the coast, as illustrated in this graphic from the National Weather Service.

Later on Monday, clouds will begin to stream from the south to the north as a developing coastal storm takes shape off the US east coast. Energy arriving from the Pacific Ocean into the Northwestern US this morning will dive into the southern US, eventually phasing with subtropical energy Monday night. This phased energy will track up the coast around digging northern stream energy that’ll take the shape of a developing upper low by the Great Lakes by Tuesday. These systems will eventually phase together as a closed low over the northeastern US Tuesday night into early Wednesday. At the surface, this upper-level scenario will allow for low pressure to develop across the US southeast Monday. This low will intensify as it tracks north towards the Carolina coast Monday evening. It will eventually pass northeast between Montauk Point on Long Island and 40 degrees latitude / 70 degrees longitude known as the “benchmark” area for major northeast storms. By Tuesday evening, this storm will be near Cape Cod as a low pressure system with pressure readings as low as the low 980mbs.

Since last night, computer guidance that meteorologists use to aid in their forecasting has shifted the storm path and structure a bit. These shifts will keep the rain/snow line from moving too far north, while also bringing the heaviest precipitation closest to the coast. The exception to this will be over far eastern Long Island, Block Island, Martha’s Vineyard, Nantucket, and Cape Cod, where mixing with sleet and/or rain will be possible at times as the storm winds up the coast. As such, snowfall accumulations there will be somewhat lower.

In terms of a heavy snowfall, coupled jet structure, approaching mid level shortwave energy, and strong frontogenetic forcing, all interacting with a significant inflow of gulf and sub-tropical moisture, will yield to very heavy snow. In parts of New Jersey and the New York City metro area, there could be some extreme heavy snowfall rates in excess of 2.5″/hour late Monday night through Tuesday afternoon.

Thunder snowstorms will form, leading to isolated bands and cells of extremely heavy snow. As these areas of intense snowfall develop, they will rob nearby areas of moisture. As such, we expect heavy snow pockets to be speckled with areas of lighter amounts around them. Remember: when thunder roars, head indoors! Lightning can kill in any season.

In addition to the shift in storm path and structure is the forward speed of this storm. This storm will be moving along somewhat faster than earlier thought. Because of the speed of the system, it won’t be able to linger around to drop historic amounts of snow. Nevertheless, snowfall will be heavy and crippling for many.

Coastal flooding is likely from the upcoming storm. As this chart from the National Weather Service shows for Atlantic City, NJ, moderate flooding and blow-out tides are possible during the storm.

Heavy snow will continue through much of the day Tuesday before wrapping up during the evening hours. A “dry-slot” will be associated with this storm and will aid in shutting off the snowfall. A dry-slot is zone of dry air which wraps east or northeastwards into the southern and eastern parts of a synoptic scale or mesoscale low pressure system and is responsible for creating the comma-like shape of a mature storm on satellite imagery. We will be tracking this development which will also have a negative impact on snowfall amounts. While the dry-slot will lead to diminished snowfall amounts, the area just north of it, nick-named the “comma-head”, will see some of the heaviest snowfall rates and amounts.

While the storm exits the northeast later Tuesday and early Wednesday, snow shower activity will persist for many on the day on Wednesday as winds howl from the northwest. These snow showers may leave additional light accumulations throughout the northeast then.

While northwest winds will howl on Wednesday, they will really roar on Tuesday as the storm system takes shape along the east coast. Wind gusts may approach 30mph as far inland as the Delaware/Maryland border and eastern Pennsylvania near Philadelphia. 40mph wind gusts are likely along and east of the Garden State Parkway in New Jersey and across all of Long Island. 40mph+ wind gusts will also be felt across much of Connecticut, Massachusetts, Rhode Island, eastern New Hampshire, and coastal Maine. Across southeastern New England, especially from south of Boston to Block Island, some wind gusts may exceed 50mph.

These winds will topple tree limbs and utility wires, possibly leading to long-duration power outages. There could also be minor structural damage, especially on exposed coastal areas. Everyone, coast and well inland, should secure any outdoor objects that may blow around in gusty winds during the storm. It is these winds that will also create blizzard conditions.

While most people associate a large snow storm with the word “blizzard”, that is meteorologically incorrect. Blizzards are defined by their winds and visibility; it is even possible to have a blizzard without any fresh snow falling. To meet blizzard criteria, bad weather conditions need to persist for more than 3 hours: namely, winds need to be at 35mph or more and visibility due to either fresh falling snow or blowing fallen snow needs to be reduced down to a quarter mile or less.

You don’t need to have blizzard conditions to have dangerous snow storm conditions. Blowing snow is wind-driven snow that reduces visibility. Blowing snow may be falling snow or it could be snow on the ground that is picked up by the wind. Snow flurries are typically defined as light snow falling for short duration with little to no accumulation while snow showers are known for snowfall at varying intensity for brief periods of time with light accumulations. Snow squalls, however, are severe, brief, intense snow showers accompanied by strong, gusty winds, and while short-lived, snow squalls can produce quick and significant accumulations. In and after snow storms, snow squalls can threaten a region with additional hazards.

The heavy snow and strongest winds should begin to wind down from southwest to northeast late Tuesday into early Wednesday as the low pressure pulls east of New England. But with snow showers and gusty northwest winds lingering into Wednesday as the phased upper low moves through, visibility may drop again from time to time in blowing snow.

In addition to a damaging wind threat, there is also the threat of significant coastal flooding, especially along the Jersey Shore, the south shore of Long Island, and southeastern New England. Some flooding could be moderate, especially at times of high tide on Tuesday. If you are in a low lying coastal area prone to coastal flooding, take appropriate steps now to protect life and property. As the storm pulls away, there is also a risk of blow-out tides, especially in the back bays of the Jersey Shore.

High and rough surf will also batter beaches leading to significant beach erosion.

Eventually high pressure will build back into the northeast later Wednesday, with fair and dry weather arriving for Thursday.

A potent storm system will impact the northeast. The storm may hug the coast or may head more off-shore; each possibility brings major changes to possible snowfall amounts. It is still too soon to say how this storm will evolve as it moves towards the northeast on Tuesday.

A major winter storm will pound the northeastern United States on Tuesday, dropping very heavy snow and whipping the coastline with damaging winds and rough surf. While Sunday and Monday will be tranquil in the northeast, it will be very cold with highs forecast to be about 15-25 degrees below normal. Meanwhile, the ingredients will be coming together for a significant storm to form off the North Carolina coast by Monday afternoon.

This storm will rapidly intensify and go through a process called bombogenesis. Bombogenesis is defined as a mid-latitude cyclone that drops in surface barometric pressure by 24 or more millibars in a 24-hour period. With an abundant moisture supply, great support from upper layers of the atmosphere, and a set-up that’s ripe for rapid development, a major Nor’easter will blossom and move up the northeast coastline late Monday evening into Tuesday. By Wednesday morning, the low pressure center should be near eastern Maine, bringing trouble to the Canadian Maritimes while the US begins the big dig-out.

Meteorologists making forecasts are aided by computer forecast models that digest large volumes of data and spit out robust data sets profiling different layers of the atmosphere; two of the most popular global models are the American (GFS) and European (ECMWF.) They each have their strengths and weaknesses, although this winter the European model has generally performed better than its American counterpart with big storms.

While we’re less than 4 days away from the storm, there’s still decent disagreement between these models and their opinions they render. The American model appears to be a western outlier, bringing a track of the primary low pressure system very close, if not a hair inland, over the coast. The European model shows a track further out to sea. A track closer to the shore line would produce much more precipitation, but it would also increase the odds of a a more northern rain/snow line that would cut snow amounts down due to non-snow such as sleet and rain falling. A track more offshore would keep cold air in place, bringing up snow totals along the coast. Tracks far off shore could also keep most of the available moisture to work with off-shore as well. At this time, the National Weather Service’s Weather Prediction Center believes a blend of those solutions will occur.

At this time, Weatherboy believes it is too early to commit to a forecast path. Beyond the complexity of the future track is the future structure of this system. Because this overall system is really the sum of many parts and it is not yet completely understood how Mother Nature will assemble those parts, there is no early, crystal-clear solution as there have been with past major storms such as the March Superstorm of 1993 and the Boxing Day Blizzard of 2010. In those storms, the pattern and available track for those storms to pursue was understood and “locked-in” several days before the storms impacted the northeast. Unfortunately, the same just isn’t true yet for this system.

There are two probable paths for the storm to pursue: hug the coast or head off-shore. In our snow maps here, we’ve illustrated how those very different paths would lay down very different snow amounts across the northeast. The coastal hugger would bring the threat of rain, sleet, or a mix of rain/sleet/snow up into New Jersey, keeping snow totals low along and south of I-95 in the Garden State south into Delaware and Maryland. But a coastal hugger would also slug more moisture inland, bringing 1-2′ snow to portions of Pennsylvania and New England. The off-shore track would pull the impacts of the storm further east, bringing the heaviest snow to portions of central New Jersey and southeastern New England. If the storm were to head even further off-shore, that heavy snow would go with it. While a well off-shore solution would eliminate change-over or mixing chances with rain or sleet, it would also cut snowfall amounts dramatically as you move away from the coast.

More data needs to be analyzed before confidence is increased in the forecast specifics, especially as it relates to snow. That confidence may not rise until Sunday afternoon. In the meantime, the National Hurricane Center has confirmed that Reconnaissance Aircraft typically used to investigate hurricanes have been deployed to this developing system to sample the atmosphere. These samples and assorted readings throughout their journey in the atmosphere will provide us with a greater level of detail of the set-up that’ll eventually impact the track and intensity of this storm.

Regardless of the storm track, the northeast will be hit by typical harsh Nor’Easter conditions: damaging wind gusts, coastal flooding, and beach erosion are all possible from the Delaware Beaches up the Jersey Shore to the South Shore of Long Island to Nantucket, Martha’s Vineyard, Cape Cod, and Block Island. While confidence is low with snow accumulation specifics, confidence is moderately high that there will be severe winds at the coast. The prime period for damaging winds would be from early Tuesday morning through Tuesday afternoon along the northeast. The best chance of coastal flooding will be during times of high tide on Tuesday.

By Wednesday, the low should quickly pull away. While the storm heads into the Canadian Maritimes, there could be lingering snow showers throughout the day, especially over northeastern Pennsylvania, northwestern New Jersey, and the higher terrain of New England. High pressure will build in during the day on Wednesday with another storm threat arriving later Thursday.

Winter storms create beautiful scenes, but also create a slew of hazards. Make sure you are weather-aware and prepared before any winter storm threat arrives.

Is a winter storm on its way to your region? The best time to prepare for it is well before any threat actually arrives.

Winter storms can immobilize a region and paralyze a city, stranding commuters, closing airports, disrupting the flow of supplies, and impacting emergency first responders. Heavy wet snow can cause roofs to collapse and force trees and large limbs to tumble down on nearby structures and power lines. Homes may be isolated for days with electricity and other utility lines cut. The cost of snow removal, repairing damages, and the loss of business can have severe economic impacts on cities and towns.

Beyond heavy snow, winter storms can also bring other weather related dangers. Nor’easters can bring heavy wind, high surf, coastal flooding, and significant beach erosion. Some well know Nor’easters include the notorious Blizzard of 1888, the “Ash Wednesday” storm of March 1962, the New England Blizzard of February 1978, the March 1993 “Superstorm” and the recent Boston snowstorms of January and February 2015. Past Nor’easters have been responsible for billions of dollars in damage, severe economic, transportation and human disruption, and in some cases, disastrous coastal flooding. Damage from the worst storms can exceed a billion dollars.

While most people associate a large snow storm with the word “blizzard”, that is meteorologically incorrect. Blizzards are defined by their winds and visibility; it is even possible to have a blizzard without any fresh snow falling. To meet blizzard criteria, bad weather conditions need to persist for more than 3 hours: namely, winds need to be at 35mph or more and visibility due to either fresh falling snow or blowing fallen snow needs to be reduced down to a quarter mile or less.

You don’t need to have blizzard conditions to have dangerous snow storm conditions. Blowing snow is wind-driven snow that reduces visibility. Blowing snow may be falling snow or it could be snow on the ground that is picked up by the wind. Snow flurries are typically defined as light snow falling for short duration with little to no accumulation while snow showers are known for snowfall at varying intensity for brief periods of time with light accumulations. Snow squalls, however, are severe, brief, intense snow showers accompanied by strong, gusty winds, and while short-lived, snow squalls can produce quick and significant accumulations. In and after snow storms, snow squalls can threaten a region with additional hazards.

When thunder roars, head indoors; lightning can kill in any season. While thunderstorms are typically associated with warmer weather, thunderstorms do pop up in intense winter storms. Lightning in a snow thunderstorm is just as dangerous as lightning in its warmer-weather sibling. The acoustics of fresh snow cover and a landscape typically free of leaves can also help make thunder sound more dramatic than it does at other times of the year. While some may be mesmerized by the sounds and scenes of thunderstorms inside snowstorms, people must remember that a thunderstorm at any time of year in any kind of weather is dangerous.

The National Weather Service is responsible for issuing weather related Warnings, Watches and Advisories for your local area. Issued by county, these advisories are based on local criteria. For example, the amount of snow that triggers a “Winter Storm Warning” in Atlanta, Georgia is much less than the snowfall required to trigger the identical warning in New York City. An Advisory generally means “be aware”; a Watch means “be prepared”; a Warning means “take action.” When a Warning, Watch, or Advisory is issued for your area, the National Weather Service will define the specific threat and will provide you with a time frame for that threat.

When a winter storm is forecast to impact your area, be sure to prepare yourself, your home, and your car. Be sure to check-in on friends, family, and neighbors –especially the elderly and others that may not be aware of the impending winter storm forecast.

Yourself

Stay indoors during the storm. Don’t venture out, especially if local officials tell you to remain at home. However, if you’re in a coastal flood threat zone and officials tell you to evacuate, evacuate! Get out as quickly and as safely as possible and get to your designated safe area.

When you do venture out after the storm, walk carefully on snowy, icy walkways.

Avoid over-exertion when shoveling snow. Heart attacks from snow shoveling are a major cause of death in the winter. If you must shovel, stretch before going outside. Make sure you’re well hydrated and take frequent breaks.

Stay dry. Wet clothing will loose all of its insulating value, allowing cold temperatures to permeate to your skin efficiently.

Watch for signs of frostbite: loss of feeling and an unusually pale appearance in your extremities. If this occurs, seek medical help immediately. Frostbite is a medical emergency! Call 911 for help if you can’t seek medical care yourself.

Watch for signs of hypothermia: uncontrollable shivering, disorientation, memory loss, slurred speech, drowsiness, and exhaustion. If these symptons appear, get to a warm location as soon as possible. Remove any wet clothing and warm the center of the body first; drink warm, non-alcholic beverage, and seek medical attention as soon as possible.

Your Home

Make sure your gutters are clean of debris.

Drain all outside hoses; shut off outside water valves where possible.

Make sure your home is well insulated; caulk and weather-strip doors and windows to keep cold air out and warm air in.

Repair roof leaks and remove tree branches that could get weighed down with ice or snow and fall on your or neighboring homes.

Wrap water pipes in your basement or crawl spaces with insulation sleeves to slow heat transfer.

Consider an insulated blanket for your hot water heater to keep water warmer longer should utilities fail.

If you have a fireplace, keep the flue closed when you’re not using it.

Have a contractor check your roof to see if it would sustain the weight of a heavy snowfall.

Make sure your furniture isn’t blocking your home’s heating vents.

Your Car

Drive only if it is absolutely necessary. If you must drive, travel during the daylight hours.

Don’t travel alone. Keep others informed of your schedule.

Stay on main roads and avoid back road shortcuts.

Top off antifreeze, windshield wiper fluid, gas, oil and other fluids. Have spare fluids in your car should you run out.

Keep bagged salt or sand in the trunk for extra traction and to melt ice.

Clear snow from the top of the car, headlights and windows. Never drive with snow on your car.

Save the numbers for your insurance agent and towing service into your cell phone. Keep a back-up on paper in your car.

Keep a cold-weather kit in your trunk. It should include a blanket or sleeping bag, gloves, hard candy, bottled water, folding shovel, first aid kit, flashlight and cell phone charger.

If you become trapped in a vehicle during a winter storm, remain inside and remain calm. Rescuers are more likely to find you there. Run the engine and heater about 10 minutes every hour; be sure to clear snow from your exhaust pipe to reduce your risk of carbon monoxide poisoning. Move around to maintain heat; use maps, floor mats, and seat covers for insulation. Drink non-alcoholic fluids to avoid dehydration. Turn on the inside light at night so rescue crews can find you. If you’re stranded in a remote area, stomp-out “HELP” or “SOS” in the snow once it’s done falling so rescue crews from the sky have a better chance of locating you.

While recent warm weather has led many to believe spring is arriving early, it is becoming more likely than not that a winter storm will bring accumulating snow to portions of the US east coast this weekend.

Details are slowly coming together for a likely east coast snow storm this coming weekend. While the odds of a storm somewhere along the east coast has increased over the last 24 hours, details of where the snow will set-up and where the rain/snow line will be remain sketchy at best. Important atmospheric data will be sampled tomorrow, helping meteorologists and some of the computer forecast guidance they use in forecasting to improve the overall understanding of a fairly complex weather pattern.

Before we get to the “main event” on Sunday, we need to deal with a fast-moving, weaker system later Thursday and Friday. A weak low pressure system originating in Canada, commonly referred to as a “clipper system”, will approach the Mid Atlantic Thursday night and exit the northeast on Friday. This system will have limited cold air and moisture to work with; as a result, precipitation will be light, and for many it’ll be in liquid form. North of I-195 and south of I-80 in New Jersey, west through Pennsylvania between I-80 and I-276/76, an inch or two of snow may fall by Friday evening, with upwards of 3″ possible in the higher terrain of central Pennsylvania. South of this area, mainly light rain is possible which could end briefly as a period of wet snow with little to no accumulations.

More importantly, this clipper system will help usher in a significantly colder air mass into the eastern US to close out the week and chill down the weekend.

Cold high pressure looks to be in place on Saturday with highs generally 10-15 degrees below normal across much of the Northeast and Mid Atlantic. The potency of this cold high pressure system and the general atmospheric flow across the continent will help determine what exactly happens on Sunday with the potential east coast snow storm.

A few days ago, the European ECMWF forecast model was calling for an all-out blizzard for portions of the eastern United States –a solution we quickly discounted. But it along with other guidance, such as the American GFS forecast model, has come around with more reasonable solutions. While not a blizzard by any means, a significant snowfall is very possible.

There are two possible scenarios for this Sunday storm.

One possibility is the cold high pressure system moving in on Saturday will help supress Sunday’s storm system to the south. Similar to a scenario that happened in January, this could bring heavy snow to portions of Virginia, especially the Hampton Roads / Virginia Beach region. Snow totals will drastically drop off to the north in this scenario, with Cape May, New Jersey on the northern fringe of accumulating snow. This scenario is supported by the latest overnight guidance from both the European ECMWF and American GFS forecast models.

The other scenario suggests that the cold high pressure system won’t be as strong; this would allow the storm system on Sunday to move closer up the northeast coast. This would shift the axis of heavier precipitation further north, but it would also bring the rain/snow line further north too. If such a scenario were to unfold, Pennsylvania and New Jersey would see the heaviest snow, with accumulating snow reaching north along the I-95 corridor, perhaps as far north as Boston. The rain/snow line would flirt with the Pennsylvania/Maryland border and southern New Jersey, keeping any snow totals in those areas low.

Until more of that atmospheric data is sampled, it is still too early to say which scenario will unfold. It is also too early to say which forecast model is “right” or “wrong”, especially with that data not yet ingested by the models. More data will come in over the next 24-48 hours which will help us improve the weekend forecast.

To recap:

A relatively weak clipper system will bring light precipitation to portions of the northern Mid Atlantic later Thursday into Friday.

This clipper system will help usher in a much colder air mass into the northeast.

Depending how strong that high is and how strong a low will be to its south will be, a snow storm is likely somewhere along the east coast; it is just too soon to say where that accumulating snow will set-up.

Forecast guidance is suggesting now that best chances for the heaviest, accumulating snow will be in southeastern Virginia. But until additional data comes in, such guidance can’t be treated as gospel.

Additional data will be in over the next 24-48 hours, which will help meteorologists solidify the weekend forecast.

The latest European (ECMWF) model suggests a significant low pressure system off the northeast coast during the middle of next week, bringing blizzard conditions to some.

A wild weather pattern is setting the stage for two more blizzards in the northeast after another potent low pressure system whipped portions of southeastern New England and Long Island with blizzard conditions.

A system later tonight into tomorrow will slide down from the Canadian side of the Great Lakes into the northeast, triggering light snow shower activity across upstate New York. Some light snow may reach south into northeastern Pennsylvania, the northern third of New Jersey, and even the metro area of New York City including Long Island. While a dusting of snow to an inch is possible on the southern side of this system, 1-3″ is possible further north into New England.

A more robust low pressure system will enter the Mid Atlantic late Saturday into Sunday, bringing rain showers to places like Pennsylvania, New Jersey, and New York. As this system makes it way to the Maine coast on Monday, cold air will wrap around the system as it rapidly intensifies south of Nova Scotia. As it does so, heavy snow will break out in Maine from this system. Snow will be thrown back to central Massachusetts and points north, where several inches of fresh snow is expected to fall. In Maine, though, 12-18″ is possible, with the most expected in eastern coastal Maine and much less in the northernmost part of the state.

With powerful winds from this rapidly intensifying system, blizzard conditions will form in eastern Maine, with strong, potentially damaging wind gusts and near-zero visibility due to heavy falling and blowing snow.

This robust system will be far enough away from New York City and places south, like New Jersey, Pennsylvania, Delaware, and Maryland, to bring any precipitation there.

After this blizzard exits the northeast on Monday, eyes will turn to yet another potential storm. Some computer forecast guidance that meteorologists use to aid in their forecasting show another strong low pressure system along the northeastern coast during the middle of the week. As with the last two systems, this next system could go through explosive strengthening, setting the stage for blizzard conditions somewhere in the northeast again.

Next week’s mid-week storm could bring another round of heavy snow whipped up by powerful winds. The best chance of snow will be in areas that saw snow from yesterday’s storm and will see snow from Monday’s storm; odds for snow are low at this time for places south of New York City and northeastern Pennsylvania, although that could change as the stormy weather pattern evolves over the next few days.

This is an illustration from one computer model that shows a snowstorm coming up the Mid Atlantic coast next weekend. However, this and other models have flip-flopped on this potential scenario, putting such a forecast in significant doubt. Image: TropicalTidbits.com

A question on many’s mind this weekend is about the weather for next weekend: will there be some type of super storm in time for the Super Bowl in the northeast? Computer model forecast guidance has been providing meteorologists with very conflicting information about whether or not a storm will form, and if it does form, where will it go.

Ingredients from the north and the south are necessary to come together to create a big eastern winter storm. Unlike the high pressure ridge that brought up unusually mild conditions up the eastern United States, a trough of low pressure is being carved out over the upper levels of the atmosphere of the Great Lakes region. Rather than transporting mild and generally wet weather up the East Coast, the trough will bring down cold and generally dry air from central Canada into the Northeast. Air originating over central Canada is a dry continental air mass, starved for moisture since there are no open oceans to tap moisture from there. As cold air pushes down into the Northeast and Mid Atlantic, most weather systems produce very little in the way of precipitation because they’re starved for moisture. The exception is the area down-wind of the Great Lakes; as that cold, dry air flows across them and picks up lake moisture as a result, Lake Effect Snow falls in the direction of the air flow. To get a robust winter storm with heavy precipitation, typically this northern “stream” of air from Canada needs to meet-up with energy and moisture from a southern “stream” from the southern United States, the Gulf of Mexico coast, or the US southeast coast.

Forecast guidance is in agreement that the cold air and the northern stream will be present; however, they dispute the existence or position of southern stream energy that could “phase” with the northern stream. Some guidance, especially data that was produced early Friday, suggested that the southern energy would be far enough along to meet-up with its northern counterpart and produce a significant snowstorm in the Mid Atlantic and New England regions. The same models have backed-off the idea, suggesting the northern stream will be so potent that it’ll suppress any activity in the south from phasing with it …or suggesting that such a phase would happen too soon or too late to create the situation that would foster a snowstorm.

Computer-generated forecast guidance is one of many tools that meteorologists use to develop their weather forecasts. While forecast guidance has been extremely inconsistent with each other or with itself run-to-run, the overall pattern change and climatological set-up does favor more a winter storm scenario than it doesn’t. Still, the right ingredients need to come together at the right time to create a significant storm, and the computer generated forecast guidance is making many loud, but early, hints that those ingredients may not all be there when they need to be.

Should a storm system form along the East Coast, it appears the best time for that to happen would be late Sunday. Wintry precipitation is unlikely in the Mid Atlantic prior to the kick-off of the Super Bowl Sunday evening. The threat of wintry precipitation arrives by midnight for the Washington, DC and Baltimore, MD areas and later in the early morning hours Monday further up the coast for places like Philadelphia and New York. This could change as we understand the overall flow across the country and the timing of northern and southern stream components, but the best chance of the most precipitation is Monday from this next potential storm.

Prior to this storm threat for next weekend, we are monitoring the potential for weaker systems beforehand. But because they aren’t tapping into southern stream energy and moisture, any such system that moves through the northeastern quarter of the country will be light. The exception, of course, will be down-wind of the Great Lakes where the Lakes are able to offer up additional moisture to very localized areas to support heavier snow.

The area in hot pink is a high-risk area for large tornadoes and tornadoes that may make long tracks. This is an extremely dangerous and rare weather event and residents in the shaded areas should prepare for life-threatening conditions.

Violent weather is impacting the nation today, with a rough 24-72 hours expected for some. The calendar says it’s the middle of January, but the eastern United States is dealing with weather situations more common in spring and fall while southern California is bracing for impact from an unusually potent storm there.

The National Weather Service’s Storm Prediction Center has made the unusual step of declaring a region in southern Georgia and northern Florida a “HIGH RISK” zone for severe weather today. The last time the Storm Prediction Center was able to declare a high-risk zone was June 3, 2014. This is coming on the heels of another rare severe event; a Particularly Dangerous Tornado Watch was issued last night, the first time such a watch was issued in January since January 22, 2012. Within this high-risk zone, there is a high probability of numerous large tornadoes; these tornadoes can also have very long tracks and bring destruction for miles and miles.

The storm system responsible for today’s severe weather in the southeast will create big headaches in the Mid Atlantic and Northeast. While severe thunderstorms and tornadoes are not expected there, damaging winds are. Winds could gust beyond tropical storm strength from Delaware north through the New York City metropolitan area and up into southeastern New England.

Numerous advisories have been issued by the National Weather Service today. They include Dense Fog Advisories (gray), High Wind Warnings (orange), Coastal Flood Advisory (bright green), and Flood Watch (dark green.) In many cases, some counties are included in multiple advisories.

Because of the likelihood of damaging winds, the National Weather Service has issued a High Wind Warning for parts of New Jersey, New York, and Connecticut. The High Wind Warning is in effect from 3am tonight/early Monday morning through to 9pm Monday evening for Middlesex and Monmouth counties in New Jersey; it is in effect from 3am through 4pm tomorrow for Atlantic, Cape May, Atlantic, Ocean and Burlington Counties in New Jersey; it is in effect from 1am Monday through to 1am Tuesday for the New York City area including Fairfield, New Haven, Middlesex, New London counties in Connecticut, Hudson, Essex, and Union counties in New Jersey, and Westchester, Manhattan, Bronx, Richmond (Staten Island), Kings (Brooklyn), Suffolk, Queens, and Nassau Counties in New York.

A High Wind Warning means winds will be sustained at 30-40mph with gusts up to 60mph. Damaging winds will blow down trees and powerlines and numerous power outages are expected. Travel will be difficult, especially for high profile vehicles.

The National Weather Service has also issued a Wind Advisory further inland, including for the metro Philadelphia area. The Wind Advisory is in effect from 6am to 4pm Monday for Gloucester, Camden, and northwestern Burlington counties in New Jersey and Delaware and Philadelphia counties in Pennsylvania. Here, winds of 25-30mph are expected with gusts up to 50mph. Strong winds even here will blow down limbs, trees, and power lines and isolated to scattered power outages are expected.

Very heavy rain will fall over New Jersey, New York, and eastern New England from this potent coastal storm.

Just off-shore, winds will really be intense; a Hurricane Wind Warning is in effect for the waters just off-shore from New York City. The Hurricane Force Wind Warning is in effect from 1pm Monday to 1am Tuesday and includes Moriches Inlet, NY to Montauk Point, NY out 20 nautical miles; Fire Island Inlet, NY to Moriches Inlet, NY out 20 nautical miles; Sandy Hook, NJ to Fire Island Inlet, NY out 20 nautical miles. Winds will gust 40-50kts with gusts up to 70kts (81mph). Seas will be extremely rough with waves 17-22 feet. Boaters are urged to head to safe port, especially small craft which may not be able to survive such fierce conditions.

Very heavy rain is also coming to the eastern United States. More than 2″ of rain is possible across the New York City metro area into central coastal New Jersey. Heavy rain will also spread into southeastern Upstate New York, southern Connecticut, Rhode Island, and the rest of eastern New England. Rain is much needed in severe drought areas here; however, too much rain over a short period of time can lead to rapid run-off and flood problems. Remember: turn around, don’t drown! Never drive through flooded roadways.

The west will also see very heavy rain today, with exceptionally heavy rain likely in areas hit hard by severe drought in southern California.

While it seems all the action is in the eastern US, that is not true today. California, especially southern California, will also be hit by a powerful storm coming on shore from the Pacific. There, more than 4″ of rain is possible in areas that usually don’t see much more than a tenth of an inch of rain at any given moment. While beneficial for the severe drought there, too much rain over a short period of time there will create widespread flooding problems.

More heavy snow is expected from the western storm; some mountains in California may see well over 3 feet fresh snow over the next 72 hours.

Rain will be the dominant precipitation type in the eastern United States, but the same won’t be true in the western United States. While cold air is absent from the east coast system, the west coast system has sufficient cold air to work with to produce very heavy snow. Portions of California may see another 3-6 feet of snow on top of 15 feet+ that has fallen just days ago.

Latest satellite image shows storm clouds gathering over the eastern US from Ohio to Florida as the coastal storm takes shape.

A significant storm along the coast of the eastern US will bring heavy rain, strong winds, and the threat of coastal and inland flooding. While many storms this time of year also produce a lot of snow, this storm is completely lacking much cold air to work with; as such, while some frozen and freezing precipitation is possible on the northern reach of this storm, plain rain will be the dominant precipitation type.

A complex area of low pres over the southern Plains and southeastern US is moving towards the east coast today. This storm will impact the east coast from later Sunday into early Tuesday, bringing a prolonged period of poor weather to a heavily populated region.

Advisory map as of 3pm shows High Wind Watches up for portions of New Jersey, Connecticut, New York, and Massachusetts.

Computer forecast guidance that meteorologists use to aid in their forecasting is aligned around the idea that there will be soaking rain, strong winds, tidal flooding and beach erosion. While confidence is high with these individual elements, the timing and magnitude of such are less certain.

Wind

One of the most widespread and potentially damaging impacts from this storm will be wind. Due to that threat, the National Weather Service offices that serve New York City, New Jersey, Connecticut, and Massachusetts have issued a High Wind Watch for parts of their forecast areas. A High Wind Watch means the potential exists for a damaging wind event; strong winds from such an event are capable of downing trees and power lines as well as causing property damage. If this watch is upgraded to a Warning for your county, be sure to stay inside and away from windows and trees.

The coastal regions from Cape May to Cape Cod along the US east coast may be especially hit hard by this coastal storm.

Across Cape Cod and nearby islands, winds of 35-45mph are expected with gusts up to 60; the greatest threat of wind damage there is late Monday morning through Monday night.

In New York City, the strong winds will arrive sooner: the greatest threat of winds, which should be in the 30-40mph range with gusts to 60mph, arrives Sunday evening and lasts through Monday evening. The National Weather Service office responsible for the New York City region warns, “Downed trees and power lines are likely, with numerous power outages possible. Travel could be difficult, especially for high profile vehicles, and on elevated roads and bridges.”

The High Wind Watch is also up for many counties in New Jersey; the National Weather Service there warns that high winds may extend far inland from the coast. While winds of 30-40mph and gusts to 60mph are possible along the coast, they warn, “Winds 20-30mph with gusts 40-50mph are possible farther inland along the I-95 corridor and in Delaware.”

Rain

Heavy rains are likely from this east coast storm; note that these totals are only through 7pm Monday and additional heavy rain is likely for portions of the Mid Atlantic and Northeast beyond then.

Heavy, soaking rains will also impact the eastern US as a result of this storm system. More than 3″ is possible in western Virginia and North Carolina, eastern Kentucky and Tennessee, and for a large part of South Carolina.

Further north, another pocket of heavy rain is expected over central and southern New Jersey, southeastern Pennsylvania, including the Philadelphia metro region, northeastern Maryland, and all of Delaware. In this pocket, 2″-3″ of rain are possible by the time the storm exits the region later on Tuesday.

The northeast is still dealing with severe drought conditions; while the heavy rain will be welcome, it won’t nearly be enough to wash away the drought conditions there.

Coastal Flooding & Beach Erosion

With strong winds, rough surf, and heavy rain, the beach communities in the Mid Atlantic and Northeast will take a beating from this storm. However, until more is known about the speed of the storm, the extent of flooding remains somewhat unknown as this time. Minor flooding is probable, especially along the ocean; but if the storm is stronger and slower, then moderate coastal flooding would be possible, especially along the ocean and back bays in central New Jersey. Strong onshore winds and battering waves could cause significant beach erosion, especially at the Jersey Shore and the south shore of Long Island. The National Weather Service says, “Confidence in the occurrence of at least minor tidal flooding is moderate.”

Wintry Precipitation

Some light snow is possible from this system. And while more snow is possible behind the forecast period of this graphic (7pm Monday), the dominant precipitation type in the eastern US from this event will be plain rain.

Wintry precipitation from this system will be limited to the northern fringes of the storm. While a light glaze of freezing rain is possible as far south as the highest terrain of northeastern Pennsylvania, any icing or sleet should change to plain rain fairly quickly. Further north where cold will be be difficult to scrub out of the mountains and valleys there, some light accumulating snow is possible across northern New England. But with a lack of cold air for this system to tap into, the dominant precipitation type in the eastern US from this storm will be plain rain.

Looking Ahead

Beyond this storm system, colder air will make its way to the eastern United States. A pattern change is expected as we move into February, with the wet and wintry weather pausing over the western United States and a colder, snowier turn occuring in the eastern United States. We have more on that pattern change here: Significant Pattern Change Arriving Soon.

A satellite image of a hurricane near the New England coast. Notice the easy to see “eye” of the hurricane. Image courtesy of NOAA

As we saw in 2016 with Hurricane Hermine in the Mid-Atlantic and Northeast and Hurricane Matthew in the Southeast, hurricane forecasts have room for improvement. This is especially true when they get as far north as the mid-latitudes and variables such as the jet stream get thrown into the mix.

The Woods Hole Oceanographic Institute (WHOI), located on Buzzards Bay in southeastern Massachusetts, in cooperation with scientists from Rutgers University, the University of Maine, the University of Maryland as well as CINAR (Cooperative Institute for the North Atlantic Region) pooled their resources on a project called TEMPEST (The Experiment to Measure and Predict East Coast Storm Strength). According to WHOI senior scientist , TEMPST had three main tools at its disposal. They are undersea gliders, buoys and ALAMO(Air-Launched Autonomous Micro Observer) floats that are released from NOAA’s hurricane hunter aircraft. According to Mr. Gawarkiewicz, a physical oceanographer, TEMPEST studied in depth the factors that contribute to storm intensity, including ocean geography, temperature, salinity, oxygen levels, water layer mixing, coastal water levels and wave patterns. The goal was to improve the intensity forecast of both tropical systems and winter storms.

To improve the forecast of a tropical system, TEMPEST needed data from when it was affecting the region. In the past, this is exactly when data was most limited. Commercial ships and planes continually send data back to NOAA (the National Oceanic and Atmospheric Administration) but avoid the area of a hurricane or tropical storm for obvious reasons. This is where TEMPEST’s technology came into play. They released their gliders, which swim through the water, buoys, and floats when the tropical systems were near.

The gliders are manufactured by Teledyne Webb Research, based in Falmouth, Massachusetts. During a tropical system or winter storm, they were deployed off of Martha’s Vineyard, off the coast of Maine, near Atlantic City, New Jersey, and also Ocean City, Maryland. These gliders take measurements underwater across the continental shelf in water approximately 100 – 300 feet deep. The glider is capable of sustaining itself at sea for about one month. This technology was used for both Hurricane Arthur and Hurricane Hermine in 2016 as these storms passed close to the Northeast.

The most surprising result of the study using the gliders for these specific tropical systems is how big of a role the continental shelf plays in the weakening or strengthening of a tropical system. According to Mr. Gawarkiewicz, “In the summer months, a cold pool of water sets under a warm surface layer where the continental shelf ends. It does not take much to bring this cool pool to the surface. A slow moving tropical system with bands of rain and wind that extend well to the north of the center of the storm can bring this cool water up to the surface ahead of the hurricane and cause it to weaken as it travels over it. Hurricane Irene in August 2011 is a great example of this.” As a result, Irene dramatically weakened as it moved northward.

In contrast to Irene was Superstorm Sandy. Occurring in late October, the ocean had already mixed, thus there was no cooler water to bring to the surface. Even with the water being churned up, Sandy did not weaken as it headed towards the coast. During the summer months, a tropical system moving fast or being rather compact won’t have as much of a chance of churning up the waters ahead of it, meaning it will sustain its strength longer than a storm like Irene.

A satellite image of a winter storm off the New England on February 9, 2013. Notice the “eye” like structure more typically thought of being associated with a hurricane.

Another asset TEMPEST employs are buoys that will measure winds, wave and sea levels both before and after a tropical system or winter storm. The goal of the buoys is to try and gather as much data as possible and combine this information with the other sources of data, such as the gilders mentioned above, satellite and radar images, and the data from NOAA’s hurricane hunting aircraft. At the present time, the team at TEMPEST is analyzing data, looking at the forecast of the storm and comparing it to the actual track and intensity of the tropical system or winter storm to try to pick up some subtle clues as to what could of been done better.

Though the meteorological factors of a winter storm are far different than a tropical system, some of the results to the average person living in the Northeast are the same. Of course, the forecasts for these winter storms, often called Nor’easters, leave room for improvement.

The buoys used by TEMPEST played a bigger role in the winter storms than they did during tropical systems. “Recreational boaters unknowingly severed the cables to many of these buoys in the days leading up to the approach of tropical system,” added Mr. Gawarkiewicz, “but there usually are not many of these boaters out during the heart of winter.” Developed by a team from the University of Massachusetts at Dartmouth, these buoys were able to give far more detailed data than previously recorded in other winter storms. Placed near Scituate, Massachusetts, Mr. Gawarkiewicz said, “The recorded wave heights were almost 11 meters (well over 30 feet) during the peak of a February 2015 Nor’easter, much higher than previously thought. And this was only hundreds of yards offshore. Recorded sea surface temperatures were in the 2-3 Celsius range above average and thus surplus warmth added more energy to this unusually strong storm.”

The ALAMO floats that were released from hurricane hunting aircraft added valuable, detailed data that were not only digested by the TEMPEST team but were sent to NOAA officials who added that data into various computer weather models. “This data provided by the ALAMO floats proved not only invaluable to our team but hopefully improved the forecasts for Arthur and Hermine”, Mr. Gawarkiewicz said.